- From: Antoine Isaac <aisaac@few.vu.nl>
- Date: Sun, 21 Feb 2010 12:12:45 +0100
- To: Johan De Smedt <Johan.De-smedt@tenforce.com>
- CC: "L.Will@willpowerinfo.co.uk" <L.Will@willpowerinfo.co.uk>, Giacomo Bartoloni <geco82@gmail.com>, "public-esw-thes@w3.org" <public-esw-thes@w3.org>, Enrico Francesconi <francesconi@ittig.cnr.it>
Hi, By the way hasn't this problem be discussed already on the list, for instance at [1], [2] or [3]? It would be nice to know whether the patterns there can fit in the discussion you have now. I think they could. By the way like Johan I don't like alternative 1. And in the STITCH project (for the RAMEAU vocabulary at [4]) we have implemented something that relates a bit to alternative 2. Both "super-vocabulary"and "sub-vocabulary" are instances of skos:ConceptScheme, but it is to the "super-vocabulary" that we have attached some extra information, not to the "sub-vocabulary". We use an extra class ConceptSchemeGrouping for that, which is a sub-class of skos:ConceptScheme and that denotes the notion of a "family" of concept schemes. Anyway, coming back to Giacomo, original question, there's no way to represent micro-thesauri 'beautifully' in standard SKOS! Cheers, Antoine [1]http://lists.w3.org/Archives/Public/public-esw-thes/2008Jan/0097.html, continued at http://lists.w3.org/Archives/Public/public-esw-thes/2008Feb/0002.html [2] http://lists.w3.org/Archives/Public/public-esw-thes/2009Jan/0036.html, continued at http://lists.w3.org/Archives/Public/public-esw-thes/2009Feb/0001.html [3] http://lists.w3.org/Archives/Public/public-esw-thes/2009Jul/0000.html [4] http://stitch.cs.vu.nl/rameau > Three alternatives and some considerations: > > 1) > The modeling of sub-thesauri in skos would be facilitated if a skos:Collection need not be disjoint with a skos:ConceptScheme. > This would allow for different sub-classes of skos:Collections > - collections that represent arrays > - collections that represent sub concept schemes or ISO like concept groups. > Note: I would NOT favor this because > - the skos:member relation mixes the skos:Collection and skos:Concept members of a collection. > - skos:Collection and skos:ConceptScheme scheme are disjoint classes > Thus making a micro-thesaurus a skos:Collection would effectively not allow to model a micro-thesaurus as a skos:ConceptScheme. > Occasionally this is not helpful because a micro-thesaurus does is a thesaurus when taken on its own. > - it would mean a change of the recommendation (while other alternatives are available - see 2) > > 2) > A new class ConceptGroup may be specified: > - Having subGroup/superGroup hierarchy possibilities next to membership > - A Concept Group would not be disjoint from skos:ConceptScheme > Note: this would be more close to the ISO DIS model Leonard refers to. > Considerations: > If some skos extension would define skos-ext:ConceptGroup, with: > - skos-ext:subGroup/superGroup properties establishing the hierarchy between these groups > - a skos-ext:inConceptGroup establishing concept group membership, > then the EUROVOC ontology can take that into account as follows: > - ev:Domain and ev:MicroThesaurus would be sub-class of skos:ConceptGroup > - the properties ev:domain/ev:microThesaurus structuring the Domain/Microthesaurus hierarchy would become sub properties of skos-ext:subGroup/superGroup > -<a-skos-ext:ConceptGroup-uri> skos:inScheme<a-skos:ConceptScheme-uri> declares the subject skos-ext:ConceptGroup to be defined by the object skos:ConceptScheme > > 3) > A separate top-level taxonomy/concept-scheme can be defined to establish the domain/micro-thesaurus (or any thesaurus top-level organization) hierarchy. > A sub-property of dc:subject (e.g. skos-ext:subjectMatch) could be applied to map the concepts of the original thesaurus to concepts of top-level (domain/micro-thesaurus) thesaurus. > The sub-property would need to define the semantics of concept-group membership. > This approach > - allows multiple classification hierarchies to be applied to an existing thesaurus. > - makes the original thesaurus independent from the used top-level classification hierarchy. > - looses the semantics that a top-level concept (domain or microthesaurus) actually can be considered as a thesaurus. > (at least in the skos universe because skos:Concept and skos:ConceptScheme are disjoint) > I would not favor this approach for a thesaurus top level organization. > - This alternative belongs more on the problem area of matching and mapping thesauri. > - skos core has a nice arsenal of (matching) properties to handle this problem area. > - The top-level organization of thesauri can be handled as explained in 2. > > Johan. > >> -----Original Message----- >> From: public-esw-thes-request@w3.org [mailto:public-esw-thes- >> request@w3.org] On Behalf Of Leonard Will >> Sent: 20 February, 2010 19:04 >> To: Giacomo Bartoloni >> Cc: public-esw-thes@w3.org; Enrico Francesconi >> Subject: Re: Doubts about domains and microthesauri in Thesaurus to >> SKOS conversion >> >> On 2010-02-18 15:11, Giacomo Bartoloni wrote: >>> Hi everybody, I'm studying the best way (or the most beautiful and >>> meaningful form) to represent a thesaurus with domains and >>> microthesauri, in my case Eurovoc and few ones, in "SKOS 2009" >> format. >>> My doubt is how to deal with domains and microthesauri, I found many >>> examples (UKAT's, IVOA vocabularies and STW's) but it seems to lack a >>> shared method to do it. >>> In UKAT thesaurus both the thesaurus and the microthesauri are >>> skos:ConceptScheme and the concepts have the property skos:inScheme >>> pointing to the main scheme and to the related microthesaurus. >>> According to IVOA all the domains and the microthesauri are >>> skos:Concept but I think that in this way I loose the base thesaurus >>> Descriptor goal and I put all domains, microthesauri and descriptors >>> on the same level. >>> In the STW's thesaurus, there is only one skos:ConceptScheme, the >>> thesaurus itself, and the domains, the microthesauri and the >>> descriptors are mapped into skos:Concept but this class is extended >>> into stw:Descriptor and ztw:Thsys. >>> >>> Which is the best thesaurus representation? >>> >>> Thanks a lot >>> >>> Giacomo Bartoloni >>> >> You might be interested to see the draft ISO 25963-1 data model, which >> I >> attach. This contains some elements that are not (yet) implemented in >> SKOS, such as ThesaurusArray and ConceptGroup. >> >> Arrays are sets of sibling terms, often grouped or ordered by some >> "characteristic of division" specified in a "NodeLable", whereas >> ConceptGroups are collections of concepts which may not be >> hierarchically related to each other, but may be subsets of the whole >> thesaurus, such as microthesauri or domains. >> >> These are described in more detail in the draft standard, which is >> available for comment until 28th February 2010 on the British Standards >> Institution web site at<http://drafts.bsigroup.com/> (Free >> registration >> required). Have a look at paragraphs 15.2.17 and 15.2.18. >> >> I hope that someone will come up with a way of incorporating these and >> other parts of the ISO model into SKOS as extensions or additions if >> necessary. I haven't yet worked out whether the The EUROVOC Thesaurus >> Ontology Schema that Johan de Smedt sent is consistent with the ISO >> model, but would be glad so see any comments. >> >> Leonard Will >> >> -- >> Willpower Information (Partners: Dr Leonard D Will, Sheena E Will) >> Information Management Consultants Tel: +44 (0)20 8372 0092 >> 27 Calshot Way L.Will@Willpowerinfo.co.uk >> ENFIELD Sheena.Will@Willpowerinfo.co.uk >> EN2 7BQ, UK http://www.willpowerinfo.co.uk/ > > >
Received on Sunday, 21 February 2010 11:13:22 UTC